//删除className(暂时没有考虑这种情况，class = "box box box1 box2")
function removeClassName ( obj, _className ) {
	if ( obj.className != '' ) {
		var arrClassName = obj.className.split(' ');
		var _index = arrIndexOf( arrClassName, _className );
		if ( _index != -1 ) {
			arrClassName.splice( _index, 1 );
			obj.className = arrClassName.join(' ');
		};
	};
}

function arrIndexOf ( arr, v ) {
	for (var i = 0; i < arr.length; i++) {
		if ( arr[i] == v ) {
			return i;
		};
	};
	return -1;
}